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(No Model.)

W. H. MARKLAND.

TELEGBAPHIG RECEIVING INSTRUMENT.

No. 260,306. Patented June 2'7, 1882.

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UNITED STATES PATENT OFFICE.

WILLIAM H. MARKLAND, OF BROOKLYN, ASSIGNOR TO JAMES E. CHANDLER AND ALBERT G. WHEELER, OF NEW YORK, N. Y.

TELEGRAPHIC RECEIVING-INSTRUMENT.

SPECIFICATION forming part Of Letters Patent NO. 260,306, dated June 27, 1882. Application filed February 24, 1882. (No model.)

To all whom it may concern Be it known that I, WILLIAM H. MARK- LAND, a citizen of the United States, residing at Brooklyn, in the county of Kings and State of New York, have invented certain new and useful Improvements in Telegraphic Iteceiving-Instruments, of which the following is a specification.

My invention relates to certain improvements in the construction of telegraphic receiving-instruments. v

The object of my invention is to provide an instrument capable of being efl'ectively operated by electric currents of moderate strength,

1 and in a novel means of adjusting the same to the requirements of any telegraphic circuit.

In carrying out my invention I make use of the well-known law that magnetisnis of like polarity tend to repel each other, and I apply this principle to two independent pieces of soft iron, constituting the core of an electrolnagnet, which are simultaneously magnetized by the current traversing the coils or helices surrounding them.

Myinvention consists generallyinconstructing an electro-magnet with a longitudinallydivided core, each section being U-shaped. One of these sections is made stationary within the coils, and the other is pivoted at or near the connecting-yoke in a manner which permits its free ends or arms to vibrate toward and from the corresponding ends of the stationary section. I provide suitable stops or contact-points for limiting the movements of 5 the movable portion of the core in each direction. The movements of the pivoted section of the core in one direction depend upon the force of gravity which causes the same to approach the stationary section, and in the other direction upon the mutual repulsion of the sections when similarly magnetized by a current of electricity traversing the coils surrounding the electro-magnet, as hereinafter more fully set forth.

5 Myinvention further consists in certain details of constructionrelating more particularly to the method of effecting the adjustments.

In the accompanying drawings, Figure l is a plan view of my improved receiving-instrument, partlyin section. Fig.2 is a longitudinal section of the same, showing the construction of the cores of the electro-magnet; and Figs. 3 and 4 represent certain details of construction.

In the figures the apparatus is shown as applied to a main-line sounder designed for operation in connection with the well-known "Morse system 5 but it is equally applicable to electromagnetic receiving-instruments of any description, as will be readily understood 6 by those skilled in the art.

Referring to the drawings, A represents the coil or coils of an electro-magnet, whichis provided with a U-shaped core constructed in two parts or sections, B and B, as hereinaf- 6 ter particularly described. The electro-magnet is preferably secured within a suitable box or case, 0, which is provided with a removable lid or cover, 0. The inclosing-case is mounted at a suitable distance above the sup- 7o porting-base D upon two trunnions, c and c, projecting from opposite sides of the case and turning in suitable hearings in the standards (I and d. The angular position of the case 0 and its inclosed clectro-magnet is regulated and controlled by means of a toothed wheel,

E, fixed upon the trunnion c, which engages with a pinion, e, mounted upon an arbor, c, and adapted to be turned by means of amilled head, 0

A check-nut, E, is provided at the end of the trunnion c, which bears against the standard d and binds the case securely in any required angular position in which it may be placed. The wheel E is preferably provided 8 5 with teeth upon one-half of its peripheryonly, thus allowing it to be turned through an angle of not more than one hundred and eighty degrees. This latter, howeverpis not a necessary construction nor essential feature of 0 my invention.

The coils A of the electro-magnet are of insulated wire wound in the usual manner, the opposite terminals being preferably soldered to the metallic plates F and F, respectively, 5 which serve to hold the lid 0 in position, and which are placed in electrical connection with the trunnions c and c by means of the screws f. The electrical connections are continued from the respective trunnions c and 0, through the standards d and d, to the binding-posts 1 I like polarity and will repel each other. The

and 2. This method of disposing of the terminals of the coils is preferred, as thereby the fine wires are entirely inclosed and are not liable to be broken or twisted off.

The core of the electro-magnet consists, as hereinbefore stated, of two parallel U-shaped sections, B and B. The projecting arms" or cores of each section are preferably of rectangular section, having a breadth several times greater than their thickness.

The cores may be constructed separately, and afterward united by a yoke or heel-piece in the usual way, but are preferably formed from a single piece of soft iron.

The stationary core-section B is rigidly attached by its yoke to a supporting-frame, G, which" is fastened to the case by screws or other suitable means. The movable core-section B is pivoted at its angles to the same supporting-frame, G, and both sections are preferably made to project a littlebeyond theends of the coils A.

Tothe free ends of the pivoted core-section B is secured a plate, h, of brass or other nonmagnetic material, provided with a projection, h, preferably extending outside the case 0, as shown in the drawings, passing through an aperture in a metallic plate, I, which'is mounted upon and preferably rigidly secured to the exterior of the case 0.

The plate I is provided with two inwardlyprojecting points, z t", against which the pro-' jection h will strike when the pivoted core-section is caused to vibrate, thereby producing sounds which may be interpreted by a skilled operator in a Well-known manner.

The longitudinal openings within the bobbins or coils A, through which the cores B B extend, are preferably rectangular in form, and of a sectional area sufficient to'permit of the necessary vibration of the free ends of the coresection B to and from the corresponding ends movement of the core-section B, is secured a plate of soft iron, K, (see Fig. 2,) which, although at no time in actual magnetic contact with the poles of the magnet, serves to attract the free ends of the section B toward itself whenever they are magnetized by a current traversing the coils.

Having thus described the construction of my improved instrument, I will now proceed to explain the operation, which is as follows: If we assume the angular position of the electro-magnet to be so adjusted by means of the mechanism provided for the purpose that the effect of the'attraction of gravity is sufficient to normally maintain the free ends of the vibrating core-section B in proximity to the fixed section, with the projection h resting againstthe stop t", then, if a current of electricity be transmitted through the magnetizing coils, the neighboring ends of the respective core-sections will be magnetized with purpose of rendering the action more reliable 'and the instrument capable of responding to more feeble currents.

That this result will be effected is evident from the fact that the magnetism generated in the core-sections causes them to repel each other, while the movable section will at the same time exert an attraction upon the soft-iron plate, causing it to be drawn toward the latter, and thus overcoming a greater opposing force than would be possible if the repellent action alone were relied upon. The plate K is not in magnetic contact with either core-section, but is dependent for its magnetization upon induction from the core. By thus detaching the plate from the cores a more rapid magnetic charge. and discharge of the same are obtained, and hence a greater rapidity in the operation of the instrument.

It is evidentthat the precise amountof force exerted by gravity upon the pivoted corescction may be nicely adjusted by turning the ad justing-screw to the right or left, and when the instrument is once placed in the required po sition the check-nut may be tightened to hold the case firmly.

In practice I have found it desirable to com struct the coils of the electro-magnets of a resistance and size dependent upon the charac= ter of the circuit in which they are to be em ployed, the relative size and number of convo lutions of wire most desirable under given con= ditions being determined by experiment or cal culation.

It is evident that the sounding-plate I and the soft-iron plate K may be made adjustable, if desired 5 but I prefer to mount each of these permanently in its required position, as all necessary adjustment may be obtained by means of the screw 0. The distance between the soft-iron plate K and the core ends should, however, be made to conform in every case to the requirements of the circuit upon which it is to be employed.

I have also found in practice that best results are obtained if the weight of iron contained in the plate K is nearly equal to that contained in one arm of the movable core-section, for the reason that the attraction between the plate and the core-section is to a certain degree dependent upon their relative masses.

I am aware that it is not new to construct an electro-magnet with one arm of its core dividedand having a pivoted section thereof actuated by means of a polar extension from the other arm.

I claim as my invention- 1. In a telegraphic receiving-instrument, the combination, substantially as hereinhefore set forth, of an electro-magnet provided with a soft-iron core constructed in two sections, one stationary and the other pivoted and free to vibrate, and an independent stationary softiron plate within the magnetic field of said pivoted section, but out of magnetic contact therewith.

2. In a telegraphic receiving-instrum en t, the combination, substantially as hereinbefore set forth, of an electro-magnet provided with a U shaped soft-iron core constructed in two sections, one stationary and the other pivoted and free to vibrate, and a non-magnetic plateuniting the free ends of said movable section.

3. In a telegraphic receiving-instrument, the combination, substantially as hereinbefore set forth, of an electromagnet provided with a U- shaped soft-iron core constructed in two sections, one stationary and the other pivoted and free to vibrate, a non-magnetic plate uniting the free ends of said movable section and provided with a projecting lip, and a stop for arresting the motion of said pivoted section.

at. In a telegraphic receiving-instrument, the combination, substantially as hereinbefore set forth, of an electro-magnet provided with a soft-iron core constructed in two sections, one stationary and one pivoted and free to vibrate, an independent stationary soft-iron plate within the magnetic field of said pivoted section, but out of magnetic contact therewith, and a stop for limiting the motion of said pivoted section.

5. In atelegraphic receiving-instrument, the combination, substantially as hereinbefore set forth, of an electro-magnet having a soft-iron core constructed in two sections, one stationary and the other pivoted and free to vibrate, an independent stationary soft-iron plate within the magnetic field of said pivoted section, but out of magnetic contact therewith, and means, substantially such as described, for controlling the angular position of said electromagnet.

In testimony whereof I have hereunto subscribed my name this 23d day of February, A. D. 1882.

\VM. H. MARKLAND.

Witnesses ISRAEL MATSON, CHARLES A. TERRY. 

